A Study on the Morphological Generation of Arch-Shaped Curvature through Slit–Strip Interlace Deformation
Sung Jin Lee, Dae Song Lee
Yonsei University DAAE, 2025
This paper examines Slit–Strip Interlace Deformation (SSID) as a planar-based bending-active transformation system in which three-dimensional curved forms emerge through the interlacing of slit flat strips rather than through an independently imposed geometry. The study begins from the view that architecture is constituted not by form alone but by the relational organization of materials and techniques, and positions SSID as an extension of this principle within contemporary digital design and fabrication. By introducing slits into planar strips and interweaving them, the system transforms two-dimensional sheets into curved surfaces while generating pre-stress, allowing form and structural stiffness to be organized simultaneously.
The research investigates SSID as a stepwise organizational process from unit to module to arch, focusing on how geometric and structural properties are generated, accumulated, and transformed at each stage. At the unit level, the study shows that slit interlacing produces a deformation homologous to a conical transformation, and that a Structural Cone Area (SCA) emerges according to the relationship among strip width, strip length, and intersection angle. This area functions as a structural core in which pre-stress is concentrated, and the analysis demonstrates that structural validity can only be maintained within an admissible geometric range defined by the W/L ratio and the angle of intersection.
These unit-level properties are extended through modular aggregation to form arches and larger surface configurations. The study finds that arch geometry is governed by the accumulation of module curvatures, expressed through a central angle, and that structural performance is maintained only when this angle remains within 180 degrees so that pre-stress continuity is preserved. At the surface scale, performance depends on the arrangement of arches: parallel assemblies with identical phases produce overlapping weak zones, whereas alternating phase arrangements distribute weakness more evenly and support structural integrity. In this sense, SSID is presented not as an open-ended form-generation technique, but as a conditional morphological organization system in which structurally performative forms emerge through specific geometric limits and arrangement logic.
